1. Field of the Invention
The present invention generally relates to a workstation suitable for being aligned with an autonomous mobile device.
2. Description of Related Art
Due to rapid progress in technology, the industry develops towards automatization, such that repeated, trivial, and toilful labour intensive work is carried out by automatic machines.
Autonomous mobile device is important for automatization. Equipped with different fittings, an autonomous mobile device is provided with special duties, and will be widely adopted. Therefore, in recent years, the development of the autonomous mobile device is increasingly highlighted. The operating time of the autonomous mobile device is mainly influenced by its power source-battery. The operating time of the autonomous mobile device is in direct proportion to the electric quantity of the battery, and the latter is further in direct proportion to volume and weight of the battery. Therefore, in order to last for a long time, the autonomous mobile device has to carry a heavy and large-sized battery, which will definitely increase the volume of the autonomous mobile device and require a greater output.
Currently, the common methods for solving the power problem and increasing the endurance of the autonomous mobile device may be generally divided into charging and battery replacement types. For example, the autonomous mobile device is charged by automatically entering a workstation. The autonomous mobile device is static in charging, and as a large electric quantity is needed, the autonomous mobile device has to be charged for a long time. However, autonomous mobile devices for duty purposes such as security patrol, plant examination, and workpiece installation, are not allowed to pause in work. In this situation, if a quick charge is performed according to requirements, the service life of the battery may be shortened.
For example, a battery charging method of a robot may be referred to in European Patent No. EP1819026 A2 “Charging System for Legged Mobile Robot”. FIGS. 1A and 1B are schematic views of a robot charging system according to European Patent No. EP1819026 A2. Together referring to FIGS. 1A and 1B, a workstation 20 has a position mark 27, the two legs of a robot 1 can move autonomously, and the robot 1 is aligned with the workstation 20 through a visual sensor. After entering the workstation 20, the robot 1 turns around to have an electrode device 4 connected to the workstation 20 and thus a battery 2 thereof is charged. A support device 23, installed on the workstation 20, has a slope opening, and may slide from left to right, so as to correct errors caused by the entry of the robot 1 into the workstation 20. After it is confirmed that the robot 1 correctly matches the workstation 20, the workstation 20 begins to charge the robot 1. If the robot 1 receives a task request before the charging is finished, it is first determined whether the task can be finished according to the workload and the remaining electric quantity of the robot 1. In this manner, if the determination result is negative, the robot 1 is continuously charged, and if the determination result is positive, the robot 1 immediately carries out the task.
Although the battery replacement type solves the stagnation problem of the autonomous mobile device, when the battery is replaced, the alignment between the autonomous mobile device and the workstation is quite important. If the deviation amount between the autonomous mobile device and the battery replacement device is too large, the battery may not be replaced successfully. If the autonomous mobile device is compulsively positioned by an external force, the autonomous mobile device or the workstation may be damaged.
For example, a battery replacement manner of a robot may be referred to in International Patent No. WO 2004/110806 A1 “Battery Replacement Device”. Referring to FIG. 2, the robot X is positioned with a bilaterally symmetrical drawing arm 140, in which the drawing arm 140 extends to hook a restraining portion A respectively on two sides of the robot X, and then a drawing portion 130 is used to draw the robot X toward a device body 120. As a positioning portion J matches a base portion 170 in cones, when the robot X is drawn into the device body 120, the device body 120 slides left or rightward along a slide rail for positioning till the positioning portion J completely matches the base portion 170, thereby achieving the purpose of precise positioning. The above manner for positioning the robot X is to draw the robot X by a drawing arm. However, if the robot X weighs too much, or the robot X has a braking device, it is impossible to position the robot X. In addition, if the entering angle of the robot X has a large deviation after reaching the battery replacement position, it is difficult for the extending drawing arm 140 to hook the robot X at the same time, and thus it is impossible to position the robot X.
In addition, for example, another autonomous mobile device may be referred to in U.S. Pat. No. 5,239,931 “Automotive Truck with Robot and Automatic Batteries Replacement System”. In this patent, a battery replacement mechanism of an automatic guided vehicle (AGV) is introduced. When short of power, the AGV has to enter a workstation to have its battery replaced. As shown in FIG. 3, it is assumed that the workstation R1 on the left side is used for installing a charged battery. After the AGV enters the workstation, the battery with insufficient power in the AGV and the battery finishing charging in the workstation together move rightward through a motor, a slide rail, and a slide screw of the workstation, such that the battery finishing charging is installed on the AGV, and the battery with insufficient power will enter a workstation R2 on the right side for charging till the AGV enters the workstation for the next time. Seen from FIG. 3, as the route of the AGV is fixed, though the AGV can be precisely aligned with the workstation through a positioning groove, the AGV may only travel along a planned route, and thus the moving function of the AGV is greatly limited.